/*
 * Copyright (c) 2022, 2022, Oracle and/or its affiliates. All rights reserved.
 * Copyright (c) 2022, 2022, Red Hat Inc. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

package com.oracle.svm.core.jfr;

import org.graalvm.nativeimage.IsolateThread;
import org.graalvm.nativeimage.c.struct.RawField;
import org.graalvm.nativeimage.c.struct.RawFieldOffset;
import org.graalvm.nativeimage.c.struct.RawStructure;
import org.graalvm.word.PointerBase;

import com.oracle.svm.core.util.VMError;

/**
 * {@link JfrBufferNode}s are added to {@link JfrBufferList}s and may have a longer lifetime than
 * the {@link JfrBuffer} that they reference. With this concept and the provided locking mechanism,
 * threads can iterate over the thread-local JFR buffers of other threads, which enables use cases
 * such as JFR event streaming.
 *
 * Note that {@link JfrBufferNode}s may be freed at safepoints. Code that accesses
 * {@link JfrBufferNode}s must therefore be fully uninterruptible.
 */
@RawStructure
public interface JfrBufferNode extends PointerBase {
    @RawField
    JfrBufferNode getNext();

    @RawField
    void setNext(JfrBufferNode value);

    @RawField
    JfrBuffer getBuffer();

    @RawField
    void setBuffer(JfrBuffer value);

    @RawField
    int getLock();

    @RawFieldOffset
    static int offsetOfLock() {
        throw VMError.intentionallyUnimplemented(); // replaced
    }

    @RawField
    IsolateThread getLockOwner();

    @RawField
    void setLockOwner(IsolateThread value);
}
